Marine air conditioner

Abstract

An air conditioning apparatus suitable for use in small boats having enclosed cabins, comprising an insulated compartment; a cooling coil having an inner surface and an outer surface; a small pump for causing a liquid cooling fluid to travel along a defined flow path leading from the insulated compartment, across the inner surface of the cooling coil, and back to the insulated compartment; and a means for causing air to flow across the outer surface of the cooling coil in heat exchange relationship with the cooling fluid. The cooling fluid is cooled by contact with a slowly melting frozen material stored inside the insulated compartment. No on-board vapor compression refrigeration cycle like those used in conventional marine air conditioning systems is used for either chilling the cooling fluid or refreezing the frozen material after it melts. This leads to a significant decrease in power requirements.

What is claimed is: 
     
       1. An air conditioning apparatus, comprising: a) an insulated compartment;   b) a heat exchanger having a first surface and a second-surface;   c) a variable-speed pump adapted to pump a liquid cooling fluid along a defined flow path leading from the insulated compartment, across the first surface of the heat exchanger, and back to the insulated compartment;   d) a means for causing air to flow across the second surface of the heat exchanger in the heat exchange relationship with the cooling fluid;   e) a computer; and   f) a temperature sensor adapted to monitor the temperature of air which has flowed across the second surface of the heat exchanger and send a signal to the computer if the air temperature varies from a predetermined set point;   wherein the computer responds to the signal sent by the temperature sensor by varying the speed of the pump; and   wherein the cooling fluid is cooled by contact with a slowly melting frozen material stored inside the insulated compartment.   
     
     
       2. The apparatus of claim 1, wherein the cooling fluid is cooled by direct contact with a slowly melting frozen material. 
     
     
       3. The apparatus of claim 1, wherein the cooling fluid is cooled by indirect contact with a slowly melting frozen material. 
     
     
       4. The apparatus of claim 1, wherein the means for causing air to flow across the second surface of the heat exchanger is a fan which blows air across the cooling coil. 
     
     
       5. The apparatus of claim 1, wherein the cooling fluid is water and the frozen material is ice. 
     
     
       6. The apparatus of claim 1, wherein the means for causing a liquid cooling fluid to travel from the insulated compartment is a pump which is powered by a rechargeable battery. 
     
     
       7. The apparatus of claim 6, wherein the means for causing air to flow across the second surface of the heat exchanger is a motorized fan which pulls air across the cooling coil. 
     
     
       8. The apparatus of claim 1, further comprising a means for collecting a liquid condensate which condenses onto the second surface of the heat exchanger from the air traveling across the heat exchanger and carrying the liquid condensate away from the air conditioning apparatus. 
     
     
       9. The apparatus of claim 5, wherein the insulated compartment comprises a drain for removing liquid water from the insulated compartment, and an opening for placing ice and liquid water into the compartment.